\begin{frame}{Capturing Dependencies}
  \begin{columns}
    \column{0.3\textwidth}
      B = f(A)\\
      C = g(B)\\
      E = f(C)\\
      F = h(C)\\
      G = g(E,F)\\
      P = p(B)\\
      Q = q(B)\\
      R = r(G,P,Q)
    \column{0.6\textwidth}
      \begin{center}
        \input{general-dep-graph}
      \end{center}
  \end{columns}
  \uncover<2>{
    \begin{tikzpicture} [overlay]
      \node [above right=1cm of current page.south west, draw,drop shadow,fill=white,
      text width=0.6\textwidth, inner xsep=0.5cm,inner ysep=0.5cm,thick]
        {
          \begin{itemize}
            \item Switch queue to out-of-order mode!

            \item Specify as list of events using 
              \texttt{wait\_for=} optional keyword
              to \texttt{enqueue\_XXX}.

            \item Can also enqueue barrier.

            \item Common use case: Transmit/receive
              from other MPI ranks.

            \item Possible in hardware on Nv Fermi, AMD Cayman:
              Submit parallel work to increase machine use.
              \subitem{Not yet ubiquitously implemented}
          \end{itemize}
        } ;
    \end{tikzpicture}
  }
\end{frame}
